The deal, signed by representatives of the Overseas Private Investment Corporation (OPIC), will pave the way for the development of a major office building program.
OPIC is a Washington, DC-based government agency that provides long term project financing to ventures involving significant equity participation by US businesses, usually with a minimum no less than 50%.
As a result of this minimum equity requirement it is normally very difficult for real estate developers to take advantage of OPIC's services.
A spokesperson for Golub and Company, the developers involved in the project, said, "We've had a lot of interest in the space already."
The center will be developed according to western design and construction standards and will provide the city with an extra 8,000 square meters (9,600 sq yards) of office space in its six stories.
It will also be the first office building in St Petersburg to have used foreign institutional financing, organizers said.
The complex is due to open later this year.